>>2618141I'm form Poznań, so I know better NW part of Poland, but what comes to my mind:
Nice wandering parts along the seaside:
1) Świnoujście - Kołobrzeg
2) Ustka - Łeba - Karwia
Nice forest + lake mix:
1) Drawski Park Krajobrazowy (a small one, but nice)
2) Bory Tucholskie
3) Kaszuby
4) Mazury (a huge region, the areas from south of Olsztyn to south of Mikołajki are less touristing can more for fooling around, lakes around Giżycko are visited rather for sailing, although there's plenty of tourist attractions as well)
Larger forests:
1) Puszcza Gorzowska (a small one)
2) Puszcza Notecka (quite the same in all parts, so it gets boring fast)
3) Puszcza Romincka (nice, but often neglected, for it's far from anywhere and it's on Polish-Russian border)
4) Puszcza Augustowska
5) Puszcza Knyszyńska
6) Puszcza Białowieska
7) Przemkowski Park Krajobrazowy (a small one, but nice)
8) Roztocze
9) Park Krajobrazowy Orlich Gniazd (features old castles ruins)
Other places:
1) Dolina Baryczy
2) Łuk Mudżakowa (the other 2/3 of it sits in Germany)
3) Polesie (I mean the Polish part, for the region spreads to the east of Poland as well)